Nematocidal composition



United States Patent NEMATOCIDAL COMPOSITION Frederick A. Hesel,Montclair, NJ., assignor to General Aniline & Film Corporation, NewYork, 'N.Y., a corporafion of Delaware No Drawing. Filed Mar. 6,1958,Ser. No. 719,518

'6 Claims. (Cl. 16733) The present invention relates to an improvednematocidal composition and to a process of applying the same.

It has been established that 3,4-dichlorotetral1ydrothiophene-Ll-dioxidemerits further trial tests for the control of nematodes in view of thepromising results obtained by laboratory, greenhouse and small plottests. This compound, which is commercially available, is a whitecrystalline solid with a very low vapor and is es- To apply theforegoing crystalline solid in the practical customary way, i.e. insolution, it has been found that its solubility in various organicsolvents is very limited with the exception of acetone. The followingillustrates the highest solubility in organic solvents at 30 C.:

Grams/100 Solvent ml. of

Solution A mtnn a 40. 6

Methyl ethyl 38.

yolnhernnrma 25, 2

chloroform. 8.0 Velsicol AR 50 (An isoparaflinic petroleum liquidhydrocarbon) 7 3.1

Acetone is impractical since it is a highly flammable liquid and thevapors of which if inhaled beyond 500 ppm. can produce dyspepsia. Methylethyl ketone is likewise a flammable liquid. The vapors of cyclohexane,which is an oily liquid, are also harmful to warm blooded animalsandman. The use of chloroform would be out of the question in view of itstoxic character and the production of burns if left in contact with theskin.

It is an object of the present invention to provide an improvednematocidal composition which may be readily applied in liquid form inthe control and eradication of nematodes.

A further object is to provide a method of applying 3,4-dichlorotetrahydrothiophene 1,1- dioxide in a non-inflammable relativelynon-toxic liquid medium so as to allow easier handling and applicationin the treatment and control of nematodes.

Other objects and advantages will become more readily apparent from thefollowing description.

I have found that liquid compounds having the following general formula:

Patented June 6, 1961 wherein Rrepresents either oxygen or an iminogroup, are excellent solvent-diluents for the3,4-dichlorotetrahydrothiophene-l,l-dioxide and that the resultingsolutesolvent combination displays a synergistic effect.

The compounds contemplated by the foregoing general formula are'y-butyrol-actone (boiling point 204 C.) and 2-pyrrolidone (boilingpoint 245 C.)'. They are neither inflammable nor primary irritants orskin sensitizers and as a result have substantially no toxicity to mostplants and mammals. When either one of these compounds is employed as asolvent-diluent for the 3,4-dichlorotetrahydrothiophene-l,1-dioxide, itdisplays little or no phytotoxic properties with the exception of somebroad leafed weeds.

The 3,4-dichlorotetrahydrothiophene-1,1-dioxide is soluble in the extentof 40-50 parts by weight of either '7- butyrolactone or 2-pyrrolidone.This unusual solubility characteristic permits the employment ofsubstantially reduced amounts of the 3,4-dichlorotetrahydrothiophene-1,1-dioxide to small areas. All that is required in such case is todissolve 40-50 parts by weight of the 3,4-di-'chlorotetrahydrothiophene-l,l-dioxide in 50-60 parts by weight of eitherthe 'y-butyrolactone or 2-pyrrolidone and dilute the resulting mixturewith an additional amount of the same solvent-diluent. Inasmuch as the'y-butyrolactone and the 2-pyrrolidone have nematocidal properties oftheir own, a synergistic effect is obtained when either one is used incombination with the 3,4-dichlorotetrahydrothiophene-l,1-dioxide.

The following example will illustrate the lack of phyotoxicity of thesolvent-diluents. All parts are percent by weight.

EXAMPLE I Two-week Old Seedlings Per- Compound cent Bean Tomato CornGrowth Suppression 2-pyrrolidone 0.1 none.. none none. 'y-butyrolactone0.1 none none none. blank none none-. none.

EXAMPLE II In order to determine the systemic toxicity of thesolvent-diluents, the following evaluation method by soil applicationwas employed:

Test plants Wgreat, soybeans, and a weed seed mixure.

Age of plants Seedlings; when soybeans are developing second trifoliateleaves.

Container Grown in 4 clay pots.

Planting method Plant 5 soybeans and 15 wheat seeds to give fine uniformplants of each species at the time of treatment. Scatter M teaspoon ofweed seed mixture on soil surface after planting.

Formulation of chemical..- Apply 45 ml. of a 0.1% solution to thesurface of one 4" pct (50 lbs. per acre).

Environment control Standard greenhouse conditions; water As notedabove, the 'y-butyrolactone and the 2-pyr- 40% solution by weight ofrolidone' are readily soluble in water. Contrary to what Example III Inorder to determine the effectiveness of the 3,4-dichlorotetrahydrothiophene-1,l-dioxide as a nematocidal agent alone,the solvent alone and the solvent-solute mixture, thefollowing procedurewas employed:

Duplicate 100 gram samples'of dry sand were mixed with gram samples of abrei of tomato roots infested with root-knot nematodes, Meloz'dogyneincognita. The brei was prepared by cutting tomato roots of infestedplants into quarter inch lengths, then further macerating in a' WaringBlendor for 1 minute. The sand and the brei were mechanically mixed byshaking 1 minute in a closed Mason jar. The mixture was transferred to 2/2 in ch clay pots at which time a certain number of milligrams of testcompound was added to the mixture. Each pot was then wrapped in Saranand allowed to stand for 24 hours. The mixture was then transferred tostainless steel cylinder screens, approximately 2 /2 inches high and 3/2 inches in diameter. The screen material was 100 mesh stainless steelwire cloth. These screens were placed in the bottom half of a 9 cm.Petri containing 25 ml. of water and covered with the Petri dish cover.In a short time an additional 10, ml. of distilled water were added toeach plate in order that free water would be available in the dish.After 24 hours microscopic counts of ten fields were vmade of the livingnematodes which had migrated through the screen and into the Petri dish.Comparisons were made with untreated control dishes and the resultsobtained are as follows:

Average Nematode Count, Dead Average Nematode Count, Living Rate 111Milligrams Compounds Fields -butyrolactone 2-pyrrolidone.

blank 3,4-dichlorotetrahydrothiophene-l,l-dioxide 40% solution by weightof 3,4-dichlorotetrahydrothiopheBe-LI-dimdde in 'ybutyrolactone3,4-dichlorotetrahydrothiophene-1,1-dioxide in 2-pyrrolidone 1' Theproduct was first dissolvedin a small quantity of acetone and theresulting solution emulsified to yield an aqueous emulsion.- Asufficient quantity of the emulsion was taken which would contain 50milligrams of the nematocidal compound. r V V In addition to the'y-butyrolactoneand 2 pyrrolidone, Iv have also found that'N-methyl-Z-pyrrolidone is the most effective solvent-diluent for the 3,4-d'ichlorotetrahydrothiophene-l,1-dioxide. As much as 60% by weight ofthe latter can be dissolved in the N-methyl-Z-pyrrolidone. Theresultingsolvent-solute combination however, does not display asynergistic efiect. This is evidently due to the fact that theN-methyl-2 pyrrolidone does'notpossess any nematocidal activity. Despitethis shortcoming, the N-methyl-Z-pyrrolidone maybe employed as a. veryeificient non-toxic, non-inflammable solvent-diluent for the 3,4dichlorotetrahydrothiophene-l,l-dioxide to yield a satisfactorysolvent-solute combination very effective as a nematocide. p

I'claim: 117A liquid nematocidal composition comprising 40 parts byweight of 3,4-dichlorotetrahydrothiophene-1,1-

v '4 v I dioxide and 60 parts by weight of a compound selected from thegroup consisting of 'y-butyrolaetone and '2- pyrrolidone.

2. A liquid nematocidal composition comprising 40 parts by weight of3,4-dichlorotetrahydrothiophene-1,1- dioxide and 60 parts by weight ofy-butymolactone.

3. A liquid nematocidal compositioninoniprising 40 parts by weight of3,4-dichlorotetrahydrothiophene-l,1- dioxide and 60 partsby weight ofi2-pyrrolidone.

4. The method of controlling soil nem-atodes which comprises contactingsaid nematodes with a liquid nematocidal composition comprising 40partsi'by weight of 3,4-dichlorotetrahydrothiophene-l,l-dioxide and 60parts 7 by weight of a compound selected from the group con sisting of-butyrolactone and 2-pyrrolidone.

5. The method of controlling soil nematodes which comprises contactingsaid nematodes witha liquid nematocidal composition comprising 40parts'by weight of 3,4-dichlorotetrahydrothiophene-1,l-dioxide and i 60parts by weight of 'y-butyrolactone. V 6. The method of controlling soilnematodes which comprises contacting said nematodes with a-liquidnematocidal composition comprising 40 parts by weight of3,4-dichlorotetrahydrothiophene-1,l-dioxide and 6.0 parts by weight of2-pyrrolidone.

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1. A LIQUID NEMATOCIDAL COMPOSITION COMPRISING 40 PARTS BY WEIGHT OF3,4-DICHLOROTETRAHYDROTHIOPHENE-1,1DIOXIDE AND 60 PARTS BY WEIGHT OF ACOMPOUND SELECTED FROM THE GROUP CONSISTING OF Y-BUTYROLACTONE AND2PYRROLIDONE.